Light Riders Being Incorrectly Upgraded into Higher Categories

Isn’t this pretty much how it is IRL? In real life, I excel on hills. The heavier riders don’t say “hey, no fair… you’re lighter!” They just tag me as a climber… and also tend to catch me on the downhill. Conversely, I often struggle with flats and sprints. Am I missing something?


Yes but I believe the original poster was saying that while in real life a lighter rider does have some advantages, in Zwift there are only disadvantages to being a lighter rider.


The funny part is that for many topics, half the arguments that will be made is that Zwift shouldn’t try to be IRL because it isn’t RL but a game; while the other half argue that of course the experience should mimic IRL. The simplest solution of course to all the weight (and height for that matter) discussion would be to eliminate these variables - that is give everyone the same 75kg weight and 180 cm height.

And a VO2 Max of 45. :blush:

Maybe within a cat… some stats from a well attended event
ht tps://

Avg Wgt and Time
A Cat: 71.8kg; 42:41
B Cat: 73.5kg; 44:27
C Cat: 77.9kg 48:28
D Cat: 84.4kg; >55:00

The format of most of the races on Zwift is different from most IRL races. Most are around 20-30km and fairly flat. They are created for power riders. When lighter riders get put in the same race as heavier more powerful riders with the same W/kg, it will feel unfair.

removing the watt floor won’t really do anything, a watt ceiling on zmap might. have spent about a year and a half thinking about it, but i will correctly assume that nobody with any pull is interested in in the how or why. if ZRS is using compound score as a control then none of this stuff be relevant anyway

Hi Mike, You have the IRL part down correct. However in Zwift, light riders don’t have that same advantage when climbing. There, we stay even with heavier climbers with same w/kg. Take a look at this short YouTube video of me and another rider from a recent race up one of Zwift’s steepest sections… the Watopia Radio Tower climb. He weighs 150, I weigh 133… so I have a 17 pound advantage, right? Outside, I would outclimb this fellow but not in Zwift. The clips shows us basically climbing at the same pace… so no advantage for the lighter rider there. But, this post isn’t about that. I’ve accepted this anomaly on Zwift, but there’s a double whammy for the light Zwift rider… the categorization isn’t respecting that same phsyics algorithm and is incorrectly thrusting us into higher categories. It’s a lose-lose for us. Here’s the short video. Simply watch our w/kg as we ride close together with little change until J.E. pushes a higher w/kg and drops me.

Video →

Hi John, you’re missing a key part of this analysis in that comparison… the watt/kg average. Take a look at this short video that shows me and another rider climbing the radio tower. He weight 150 to my 133. You would think at the same w/kg that I would climb faster, no? The video will show that I can simply just stay even… so no advantage there for the lighter rider. This was documented by a Zwift Insider article a couple years back and I’ve accepted that. This post is about applying the same physics algorithm to the categorization logic. Here’s the sample video:

I’m not sure why that would be the case. If you’re normalizing for weight (by using power/weight), then why would you assume you can climb faster at the same power to weight ratio? I would expect you would climb faster than them when you both do the same power though.

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I’m a software programmer by trade so rationalize that Zwift is using some complex algorithm for each of us throughout every ride to determine our speed. There are certainly many variables… weight, grade, draft, bike, height, power, etc, etc. That’s all fine.

Please apply that same algorithm when determining what category we “truly” belong in. That’s all. Seems like a fairly simple change. Stop using the current w/kg and min/max watt ceilings, and instead use the same logic with the categories. This is currently a terrible inconsistency between the real-time event calculation vs the post-event/category calculation.

Zwift, would love it if you gave this some attention. The lighter crowd is hanging there with these regular beatings but I’m certain we’ve lost many who have given up and moved on to other platforms. Let’s please fix this.

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Yes, great idea. I’m 165 cm and 56 kg. Making me 75kg and 180cm seems COMPLETELY fair. At least it would be upfront about giving big folks and advantage while screwing lighter riders.


Well, if they did just use power (normalizing weight and height for the riders in the group), what they would be able to do is just have power-based categories with no ability to weight dope, so riders who push less power (whether they are lighter or heavier) would go into a lower category and compete with others at the same raw power output. So I guess maybe that is better than being pushed into a flat race by a w/kg metric maybe? It would in no way represent what would happen IRL in this case though, large riders who push a lot of power would fly up hills like they can’t ever do IRL if they did this.

I’d prefer they just use compound score for seeding, and race rankings to categorize people, and I’d also prefer the categories be less static in the major races rather than people having a consistent target to sandbag their numbers to stay inside a cat.

Admittedly I don’t have a solution but it is currently broken for lighter riders. I used to do races up the Alpe but would always lose to a B or C rider putting out 300+ watts. They’d always get a waiver but i put out 225 watts and I’d get flagged and DQ’d. The light rider disadvantage is so bad that coffee breaks don’t even keep me in a pack on descents. It fails EVERY time.

that doesnt do anything except annoy one or two people. it just moves some people up or down a category. i was particularly irritated at people giving me ■■■■ about my weight one day and wondered what would happen if i changed my weight to something less conspicuous and reinvented myself as C rider for some peace and quiet, so i ran the numbers myself already

that aside, who really gets shafted every time the goalposts move? i just spent two whole years explaining CE to normal people who got shafted by a system they did not understand. i understood it within two weeks of learning what critical power ever was. some people in this very thread were more than happy to take my advice on CE when it affected them personally, too.

so i can say with 100% certainty that for every degenerate caught out by a change in the category system, 50 normal people are too

SeattleSauve, I believe at some point, gravity and lighter weight begins to help the lighter ride on steep climbs. I believe 6% grade and higher is the number I’ve seen somewhere. So IRL, I have witnessed a benefit but not here.

Your second comment… both riders having the same power? Yes, totally agree there. If I weigh 133 lb and put out 200 watts, that’s a 3.3 w/kg average. A larger rider 200 lb rider of similar w/kg is putting out 300 watts. I would love to have those 300 watts… That would then give me a 5.0 w/kg to their 3.3 w/kg and I would scoot ahead and be thanking Zwift. :slight_smile:

Right, it helps the rider because the metric to estimate performance shifts to w/kg, so then the lighter rider has to push a lot less power than the heavier rider. So where on flat you’re more concerned with Aero and pure watts, which doesn’t help the lighter rider as much, on a climb the performance can be better characterized by power to weight which absolutely makes a huge difference.

So two riders of different weights might be able to stick together at a similar power on flat if they are similarly aero, but once you hit the hills (particularly above 6%) you will see that w/kg becomes the better metric to estimate performance, and that helps the lighter rider, if they keep the same power the heavier rider will fall away on the hill.

So lighter riders absolutely get an advantage on climbs given w/kg - means you no longer need to push as much power as a heavier rider in pure watts, but where it sucks in Zwift for lighter riders is that all races are categorized by w/kg boundaries, and most races are flat, so it’s hard for a lighter rider to do great on a flat race without getting upgraded to the next category.

SeattleSuave, have you watched the video I posted showing me and another rider (17 pounds heavier) climbing a 13% grade? There’s no advantage there on Zwift. Take a look. Agree with all other excellent points.

Do the laws of physics support your belief that a lighter rider climbs faster than a heavier rider if both are climbing at exactly the same w/kg.

I can only find articles which say the opposite.


Same W/kg given a steep enough climb should climb at the same pace. On Zwift a lighter climber is at a disadvantage at the same W/kg on all gradients and always has to put out more W/kg.

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